A pneumatic-tired tractor with a 354 - hp engine has a maximum speed of 3.6 mph in 1st gear. Determine the max. rimpull of the tractor in each gear if the engine effieicency is 91%. (1st gear = 3.8 mph, 2nd gear = 6.5 mph, 3rd Gear = 11.5 mph, 4th Gear = 20 mph).
Also, if the tractor weighs 31.7 tons and is operated over a haul road having a slope of +1.2% and a rolling resistance of 84 lb/ton, determine the maximum external pull by the tractor in each of the four gears.